Television and other audio/visual entertainment or information services are now provided to users via a variety of routes, for example via cable, telephone line satellite or over-air broadcast. Set top boxes are generally used to receive and process signals and to provide outputs to cause a television set to display a selected stream of content.
As the number of television channels and other services have increased, set top boxes have become increasingly more sophisticated and provide a range of functions to the user. In many cases a set top box is provided to a user as part of a subscription package provided by a service provider. Often the service provider retains ownership of the set top box and is responsible for maintenance and replacement of the set top box in the event of faults.
In the case of faults in a set top box reported by a user, a service provider usually sends an operative to the user's home to inspect the set top box. Existing test systems are not suitable for testing set top boxes in situ, and in the event of a reported fault boxes are usually replaced rather than tested or serviced at the user's home. The previous set top box is then sent to a central facility for testing. If the testing reveals that there is no fault, or if the fault is easy to rectify, the set top box can then be provided, as new, to another user, subject to replacement of outer casing if necessary.
When a user terminates a subscription package, the set top box provided as part of the package is also sent to the central test facility, and if testing reveals no faults it is again provided, as new, to another user. If testing reveals faults then either the faults are rectified or the set top box is discarded.
In the UK, more than a million used set top boxes are tested each year, disregarding any testing that may take place as part of the manufacturing process. In the US, there are many more set top boxes per head than in the UK and the numbers of set top boxes tested are greater. In Texas alone, for example, more than 20 million used set top boxes are tested each year.
The testing of set top boxes is a major expense for service providers or set top box manufacturers, and any increase in the speed of testing can produce significant cost savings. It is also important that testing is accurate, as any inaccuracies in testing can result in faulty set top boxes being returned to users. For service providers in particular it is very important that the fault levels of set top boxes do not become too high, as that can have a significant impact on the level of user satisfaction.
In a known set top box testing facility, conveyor belts are used to transfer set top boxes to and from testing stations. Each testing station comprises a rack including a PC running test software, a mounting point for mounting a set top box to be tested, a screen for connection to the set top box for outputting video content provided via the set top box, and a network connection for connecting the set top box to a head end server within the site.
Upon receipt of a set top box from the conveyor belt, an operator mounts the set top box on the testing station, and connects it to the screen, the network and other components needed for testing. A test program running on the PC instructs the operator to perform a sequence of tests and the user can log the results of the tests using the testing program. The tests can include checking that the set top box powers up and initialises correctly, checking that the buttons on the front of the set top box work correctly, and checking that the set top box received infra-red remote control signals correctly, usually by operating each of the buttons on a remote control unit in turn and checking for the correct response.
In addition to the testing of the basic operation of the set top box, the operator also tests the quality of the video and audio output by the set top box. The head end server provides audio/visual content to the set top box and the operator views the video content on the screen connected to the set top box, and listens to the audio content, usually via headphones. The operator provides a subjective assessment of whether he considers the video and audio output to be of acceptable quality. The operator is trained to assess the audio/visual content in comparison with pre-determined criteria. The criteria and the content to be used for testing is usually selected by the service provider or set top box manufacturer.
Most of the tests are performed manually by the operator or rely on operator judgement, and thus are subjective. For example, the testing of audio/visual content in known systems is subjective and outcomes can vary from operator to operator and over time (for example, in dependence on the level of attentiveness of the operator on different days or different times of day). Furthermore, as an operator becomes more familiar with a test over weeks or months their assessment of what is or is not acceptable set top box performance can change, and the assessments of different operators can begin to diverge. In addition, each time a new product is to be tested or a new test is to be introduced operators must be retrained.
Furthermore, certain faults in the reproduction of audio/visual content can be harder or easier to spot depending on the type of content being displayed. For example, missing or frozen frames may more apparent when viewing, for example, sporting events than when viewing test patterns. Some faults may not be apparent when viewing content at normal speed in a test procedure but may be clear to a user when replaying recorded content, for example in slow motion.
It is an aim of the present invention to provide an improved or at least alternative testing apparatus or method.